Infrastructure Engineering - Research Publications
Permanent URI for this collection
Search Results
1 - 10 of 21
-
ItemHigh water use plants influence green roof substrate temperatures and their insulative benefits(Elsevier BV, 2023-12-01)Green roofs are amongst the solutions employed to deliver sustainable buildings in cities. Their vegetation and substrate layers can reduce the heat transfer through the roof, thus potentially reducing energy used for building cooling and heating. However, little research has investigated the insulative properties of drought-tolerant plants which also have high water use. These plants have been found to improve runoff retention by removing larger volumes of water from the substrate through higher transpiration rates than succulents. This planting strategy may also enhance green roof cooling performance due to their greater evapotranspiration rates. In this study, the thermal performance of three drought-tolerant species with high water use — Lomandra longifolia, Dianella admixta, and Stypandra glauca — was evaluated and compared with a commonly used succulent species (Sedum pachyphyllum) and a bare unplanted module. L. longifolia had the best insulative performance during the entire investigated period, reducing green roof substrate surface temperature up to 1.86 °C compared to succulent S. pachyphyllum. In summer, the mixture reduced heat gain to a greater extent than monoculture plantings of all species except L. longifolia. Summer measurements also suggest that plants with high leaf area index (LAI) and higher albedo should be selected to reduce surface temperatures. High evapotranspiration rates of high water use L. longifolia led to greatest reduction of bottom surface temperatures during a heatwave when decreasing its water content from 18.5% to 2.9%. Results obtained using an analytical hierarchical partitioning technique indicated air temperature had the most significant impact on temperatures at both the surface of the planting substrate and the bottom of each green roof unit, accounting for 48% to 58% of the variation.
-
ItemComparison of waste photovoltaic panel processing alternatives in Australia(Elsevier BV, 2023-09-15)This work aims to compare end-of-life (EoL) alternative processing scenarios of waste photovoltaic panel in Australia. Landfill, generic waste electrical and electronic equipment recycling (European business-as-usual (EU BAU)), full-recovery EoL photovoltaic (FRELP), and Modified FRELP are the alternative processing scenarios considered for the next five years. Environmental analysis by a simplified life cycle assessment is performed using Material, Energy, Chemical, and Other (MECO) matrix. This semi-quantitative comparison eliminates reliance on LCA software and environmental expertise for preliminary screening. Financial analysis is also performed by using a life cycle costing (LCC) approach. Overall, comparative findings are consistent with full-quantitative LCA and LCC despite magnitude differences. Simplified analysis merely reflects process complexity and resource consumption. A full financial insight can only be acquired when non-resource-derived costs are incorporated. Considering the increasing trend of waste levies and landfill ban extending into the future, landfill is no longer the cheapest option in Australia. Consequently, mass-based waste recovery for landfill diversion facilitates cost savings. Recovering 8% more waste with FRELP compared to modified FRELP has the potential to save $19 more per tonne of processed PV waste. EU BAU is the most eco-efficient interim solution, while waste volume is still low. Modified FRELP saves 321 kg CO2-e emission by avoiding traditional incineration. The focus on reclaiming solar-grade silicon rather than silver has the potential to attract $154 more revenue per tonne compared to FRELP.
-
ItemEfficient HVAC system identification using Koopman operator and machine learning for thermal comfort optimisation(Elsevier BV, 2023-08-15)The aim of this article is to improve the efficiency of heating, ventilation, and air conditioning (HVAC) systems by using a linear control approach. Conventional HVAC systems use a wall thermostat and a simplified ON/OFF controller to condition the thermal environment, but this approach is not always efficient in meeting indoor heat loads. To address this issue, we propose using the Koopman operator combined with Machine Learning, a linear embedding method, to model the nonlinear behaviour of thermal comfort indices. Specifically, we use the Predictive Mean Vote (PMV) index, which has been a superior indicator of occupants’ thermal sensation. We apply Computational Fluid Dynamics to create high-dimensional training, testing, and validation datasets, and a deep autoencoder network framework to map the original nonlinear coordinates of the PMV index into a latent space where the system is behaving linearly. Our results show that the Koopman autoencoder can reproduce and predict data from the latent space, enabling offline system identification for the zone thermal conditions and this has the potential to improve HVAC feedback control systems.
-
ItemNo Preview AvailableFire safety performance of 3D GFRP nanocomposite as a cladding material(ELSEVIER SCI LTD, 2022-10)Vertical fire spread along highly flammable claddings is a major safety issue for buildings. In this project, a potential new type of cladding material, 3D Glass Fibre Reinforced Polymer (3D GFRP) with improved thermal stability, and fire performance is developed. 3D GFRP nanocomposite samples were fabricated with different percentages of Sepiolite (Sep), Sepiolite-phosphate (SepP), Ammonium Polyphosphate (APP) flame retardant, and 3D glass fabrics. Synthesis of SepP, dispersion analysis of nanoparticles, and manufacturing process have been studied. The characterisation of materials was conducted using Scanning Electron Microscopy, Helium Ion Microscopy, Transmission Electron Microscopy, Thermogravimetric Analysis (TGA), and X-ray Diffraction Analysis. The thermal stability and fire behaviour of the 3D GFRP nanocomposite was studied via TGA and cone calorimeter test. TGA results showed that the optimum amount of additives that improved the thermal stability is 15% flame retardants. Results of cone calorimeter tests showed that different percentages of APP, Sep, and SepP decreased the peak of the heat release rate between 4% and 42%. Also, the effects of APP flame retardant in improving thermal and fire reaction properties were more than Sep and SepP. The test results of 3D GFRP nanocomposite also showed a prospective cladding that can benefit the construction industry in near future.
-
ItemNo Preview AvailableThe life aquatic(AIRAH, 2023-05-01)Students and academics from the University of Melbourne joined forces with industry consultants and local government representatives to explore achieving net zero carbon design for those most energy-intensive buildings: aquatic centres. The university’s Brendon McNiven, Dominik Holzer and Lu Aye, F.AIRAH, elaborate.
-
ItemThermal and energy performance evaluation of a full-scale test cabin equipped with PCM embedded radiant chilled ceiling(Elsevier BV, 2023-06-01)The escalating global demand for space cooling has led to the emergence of new cooling technologies, including the phase change material embedded radiant chilled ceiling (PCM-RCC) system. This technology improves energy efficiency and indoor environmental quality, while also offering demand-side flexibility. The present study experimentally evaluates the thermal efficiency and energy performance of a PCM-RCC system in a full-scale test cabin equipped with PCM panels. Here, the transient thermal behaviour of PCM ceiling panels besides the cooling energy delivered during charging-discharging cycles are examined. The indoor thermal comfort and peak electricity demand reduction enabled by the present PCM-RCC are also discussed. The results reveal that chilled water circulation for 4–5 h overnight was sufficient to fully recharge the PCM panels. Over 80% of the occupancy time was classified as “Class B″ thermal comfort according to ISO 7730. The system's daily electricity usage was mostly concentrated during off-peak hours, accounting for ∼70% of the total usage. While the controlling schedule used in this study responded to the transient thermal behaviour of the indoor space and PCM ceiling panels, a more dynamic, predictive schedule is necessary to improve the system's overall efficiency and further enhance indoor thermal comfort in response to the changing environmental conditions.
-
ItemNo Preview AvailableEmergency(Australian Institute of Refrigeration, Air Conditioning and Heating (AIRAH), 2022-10-31)As part of the i-Hub project, masters-level architectural and engineering students from the University of Melbourne, industry consultants, university academics, and Ambulance Victoria staff embraced the challenge of designing net zero emergency response stations. The university’s Brendon McNiven; Lu Aye, F.AIRAH; and Dominik Holzer discuss.
-
ItemNo Preview AvailableUpcycling opportunities and potential markets for aluminium composite panels with polyethylene core (ACP-PE) cladding materials in Australia: A review(ELSEVIER SCI LTD, 2022-11-28)Many buildings worldwide have high fire-risk materials as part of their cladding. As governments in Australia strive to make buildings safer, it is expected that a large volume of end-of-life dangerous cladding will be replaced with safer materials. This high volume of hazardous materials might be upcycled into value-added products. This article presents a systematic market analysis and literature review in identifying current and potential uses for the raw materials used in hazardous ACP-PE cladding. The most promising areas were identified to be non-food-contact packaging (US$228 M p.a.), non-pressure pipes (US$30 M p.a.), footwear (US$5.29 M p.a.) and 3D printer filament (US$2.73 M p.a.)
-
ItemEffects of Working from Home on Greenhouse Gas Emissions and the Associated Energy Costs in Six Australian Cities(MDPI, 2022-04)Working from home (WFH) has been imposed due to the COVID-19 pandemic. The adoption of WFH impacts energy use in the residential, commercial, and transportation sectors. Consequently, this affects the greenhouse gas emission (GHGE) and the associated energy costs to workers and employers. This study estimates the effects of WFH on the GHGE and energy-related costs in the residential, commercial, and transportation sectors. A simple linear model was used to estimate the changes in the GHGEs and cost by a typical employee when WFH practice is adopted for 1.5 and 4 days per week. The adoption of WFH reduces the operational GHGE accounted for commercial buildings and transport. However, it increases the operational GHGE accounted for residential buildings, which is a maximum of about 6% and 12%, respectively, for WFH 1.5 and 4 days. The reduction of GHGE from transport is significantly higher than that of residential buildings. The GHGE reductions from the transport sector are about 30% and 80%, respectively, for WFH 1.5 days and 4 days per week. WFH for 1.5 and 4 days per week reduces the national annual GHGE by about 1.21 Mt CO2-e and 5.76 Mt CO2-e, respectively. Further, the annual transportation cost of an employee is reduced by 30% and 80% in each city when the employee WFH for 1.5 and 4 days per week. The outcomes of this study offer a direction to reduce energy consumption and related costs and potential future research avenues on this topic. Further, the findings also help policymakers develop a hybrid work model for the post-COVID-19 pandemic.
-
ItemNo Preview AvailableEffects of learning curve models on onshore wind and solar PV cost developments in the USA(PERGAMON-ELSEVIER SCIENCE LTD, 2022-05)Technological innovation planning for developing and deploying clean energy technologies plays a key role in reducing greenhouse gas emissions and transition to a low-carbon future. Learning curve theory has been adopted as a common framework for exploring the relationship between endogenous technological learning and technology cost developments. The aim of this article is to analyse the effects of selecting different learning curve approaches (i.e. model formulations) to describe energy technology cost changes over time. Experience and knowledge stock are chosen as the sources of learning to be considered. A new definition of experience was developed to account for the interaction between global and local experience. The new definition of experience also accounts for learning sub-processes (i.e. learning-by-doing, learning-by-using, and experience spillovers) to estimate total experience gained through technology deployment. An integrative model is developed for estimating the effects of learning-by-deploying and learning-by-researching on cost developments for onshore wind and solar PV in the USA. Publicly available data from government departments and organisations were utilised. It was found that technology cost developments are better explained when: (1) experience is defined as a function of global and local experience; (2) knowledge stock is also considered in the model formulation; and (3) technological processes affect only a fraction of the total capital cost. The findings suggested that the application of learning rates for model-based energy planning is context-dependent and how technological factors are explicitly defined may have significantly different policy implications (i.e. different technology costs predictions based on alternative model formulations).